cumulative sales for two months

[BrahmanandaRao]

Data Prdsales;
input prdcode $ Jan_sale Feb_sale;
cards;
P101 230 450
P102 340 320
P103 210 250
;
run;

proc sort data=prdsales ;
by prdcode;
run;

data sales_cum;
set prdsales;
by prdcode;
if first.prdcode=1 then cumsale=0;
cumsale+jan_sale;
run;

/*QUESTION1:-How to calculate cumulative sales for each month in the above code
i            i want to caluculate jan_sale and f_sale for each month cumulative sales?

[Kurt_Bremser]

Use PROC MEANS/SUMMARY:

proc means data=prdsales nway;
class prdcode;
var jan_sale feb_sale;
output out=want (drop=_type_ _freq_) sum()=;
run;